scholarly journals Internal Energy Level Population Redistribution of Carbon Dioxide in Laminar and Turbulent Flow

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Wisely Wong ◽  
Zhiyu Yang ◽  
Amador Muriel
Keyword(s):  
Carbon Dioxide ◽  
Energy Level ◽  
Internal Energy ◽  
Flow Rate ◽  
Population Distribution ◽  
Energy Levels ◽  
Level Population ◽  
Laminar To Turbulent Transition ◽  
Turbulent Transition ◽  
Laminar And Turbulent Flow

We show clear experimental evidence that in the laminar flow regime, there is a continuous redistribution of population on different vibrorotational energy levels as the flow rate increases. Such redistribution comes to an abrupt stop when the flow changes to turbulence. The population distribution then remains almost unchanged even up to the flow rate 10 times the laminar to turbulent transition. The flow status of carbon dioxide is therefore closely related to its internal energy level population distribution.

scholarly journals Interpretation of the level population distribution of highly rotationally excited H2 molecules in diffuse clouds

1992 ◽  
Vol 150 ◽  
pp. 157-158
Author(s):  
R. Wagenblast
Keyword(s):  
Vibrational State ◽  
Population Distribution ◽  
Energy Levels ◽  
Level Population ◽  
Excitation Mechanisms ◽  
Diffuse Clouds

The observed H2 level population distribution of the rotational levels J = 5, 6 and 7 in the ground electronic and vibrational state X(v = 0) is analysed using available Copernicus data (Spitzer and Morton, 1976) for the diffuse clouds toward the stars ζ Oph, δ Per and ξ Per. The abundances of H2 in these high purely rotationally excited energy levels are due to the influence of one or more of three possible excitation mechanisms: collisions with abundant particles (e.g. H atoms and H2 molecules), UV-photoexcitation and H2 formation.

Numerical Simulation of the Performance of an Axial Compressor Operating With Supercritical Carbon Dioxide

2018 ◽  
Author(s):  
Jinlan Gou ◽  
Wei Wang ◽  
Can Ma ◽  
Yong Li ◽  
Yuansheng Lin ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Supercritical Carbon Dioxide ◽  
Critical Point ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Axial Compressor ◽  
Brayton Cycle ◽  
Supercritical Carbon

Using supercritical carbon dioxide (SCO2) as the working fluid of a closed Brayton cycle gas turbine is widely recognized nowadays, because of its compact layout and high efficiency for modest turbine inlet temperature. It is an attractive option for geothermal, nuclear and solar energy conversion. Compressor is one of the key components for the supercritical carbon dioxide Brayton cycle. With established or developing small power supercritical carbon dioxide test loop, centrifugal compressor with small mass flow rate is mainly investigated and manufactured in the literature; however, nuclear energy conversion contains more power, and axial compressor is preferred to provide SCO2 compression with larger mass flow rate which is less studied in the literature. The performance of the axial supercritical carbon dioxide compressor is investigated in the current work. An axial supercritical carbon dioxide compressor with mass flow rate of 1000kg/s is designed. The thermodynamic region of the carbon dioxide is slightly above the vapor-liquid critical point with inlet total temperature 310K and total pressure 9MPa. Numerical simulation is then conducted to assess this axial compressor with look-up table adopted to handle the nonlinear variation property of supercritical carbon dioxide near the critical point. The results show that the performance of the design point of the designed axial compressor matches the primary target. Small corner separation occurs near the hub, and the flow motion of the tip leakage fluid is similar with the well-studied air compressor. Violent property variation near the critical point creates troubles for convergence near the stall condition, and the stall mechanism predictions are more difficult for the axial supercritical carbon dioxide compressor.

scholarly journals Gaseous combustion at high pressures. —Part X. The co-volume corrections, maximum temperatures and dissociation of steam and carbon dioxide in explosions

1928 ◽  
Vol 119 (782) ◽  
pp. 464-480
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Internal Energy ◽  
High Temperatures ◽  
High Pressures ◽  
Internal Combustion ◽  
Systematic Survey ◽  
Explosion Method ◽  
Maximum Temperatures ◽  
Very High

During the researches upon high-pressure explosions of carbonic oxide-air, hydrogen-air, etc., mixtures, which have been described in the previous papers of this series, a mass of data has been accumulated relating to the influence of density and temperature upon the internal energy of gases and the dissociation of steam and carbon dioxide. Some time ago, at Prof. Bone’s request, the author undertook a systematic survey of the data in question, and the present paper summarises some of the principal results thereof, which it is hoped will throw light upon problems interesting alike to chemists, physicists and internal-combustion engineers. The explosion method affords the only means known at present of determining the internal energies of gases at very high temperatures, and it has been used for this purpose for upwards of 50 years. Although by no means without difficulties, arising from uncertainties of some of the assumptions upon which it is based, yet, for want of a better, its results have been generally accepted as being at least provisionally valuable. Amongst the more recent investigations which have attracted attention in this connection should be mentioned those of Pier, Bjerrum, Siegel and Fenning, all of whom worked at low or medium pressures.

Radical induced intermolecular linkage and energy level modifications of a porphyrin monolayer

2017 ◽  
Vol 53 (6) ◽  
pp. 1104-1107 ◽  
Author(s):  
Abdolreza Jahanbekam ◽  
Colin Harthcock ◽  
David Y. Lee
Keyword(s):  
Energy Level ◽  
Scanning Tunneling Microscopy ◽  
Surface Structure ◽  
Energy Levels ◽  
New Method ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Molecular Scale

A new method to directly modify the surface structure and energy levels of a porphyrin monolayer was examined with molecular-scale resolution using scanning tunneling microscopy and spectroscopy (STM and STS) and presented in this communication.

VIBRATIONAL ENERGIES OF MEMBERS IN STRUCTURAL NETWORKS FITTED WITH TUNED VIBRATION ABSORBERS

2006 ◽  
Vol 06 (02) ◽  
pp. 269-284 ◽  
Author(s):  
SUNNY K. GEORGE ◽  
K. SHANKAR
Keyword(s):  
Energy Level ◽  
Vibrational Energy ◽  
General Structure ◽  
Energy Levels ◽  
Complex Structure ◽  
Input Power ◽  
Vibration Absorbers ◽  
Tuned Vibration Absorbers ◽  
Vibrational Energies ◽  
Structural Networks

The distribution of vibrational energy in members of a complex structure with tuned absorbers attached at the joints and subjected to dynamic loading is studied. The concept of power flows through the structure is used to determine the time-averaged energy levels of each member in the structure. The power flows are calculated using the time-averaged product of force and velocity at the input and coupling points (joints) of a general structure made of axially vibrating rods. The receptance approach is used to calculate the coupling forces and velocities in the structure. By balancing the input power against the dissipated powers, the time-averaged energy levels in members are determined. The main criteria studied here is the reduction in the frequency-averaged vibrational energy level of a member when an absorber is attached, expressed as a percentage compared to the case where there are no absorbers. The concept is first illustrated with a simple model of 2 axially vibrating rods with an absorber attached to the joint. Next, a more complex structure comprising 8 rods with arbitrary orientations and several absorbers attached to junctions is studied. The effect of activating absorbers at various locations on reducing the energy levels of certain members is examined. It is possible to estimate the usefulness of the absorber with respect to any member by determining the percentage reduction of energy level for that member.

PREPARATION AND CHARACTERIZATION OF Zr-DOPED TiN NANOFILM

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3455-3458
Author(s):  
ANPING LIU ◽  
YINFENG WANG ◽  
XUEHENG YANG
Keyword(s):  
Thin Film ◽  
Corrosion Resistance ◽  
Energy Level ◽  
Mixed Crystal ◽  
Energy Levels ◽  
Energy Band Structure ◽  
Reactive Magnetron ◽  
Tin Coating ◽  
New Energy

The Zr -doped TiN coating, a nanometer (Ti, Zr)N thin film, has been deposited by reactive magnetron sputtering on slides and Al substrates. The crystalline phase and energy band structure have been analyzed by XRD and STS. The results of XRD show that the (Ti, Zr)N film is poly crystalline and consisted of mixed crystal of TiN and ZrN phase. The STS spectra show that Zr -doping didn't change the position and band-gap of energy level, only two new energy levels appeared, Eg = 0.33eV and Eg = 0.42eV. According to the results of measurement, (Ti, Zr)N has higher hardness and better corrosion resistance than TiN by Zr -doping.

Laminar to turbulent transition in a finite length square duct subjected to inlet disturbance

2021 ◽  
Vol 33 (6) ◽  
pp. 065128
Author(s):  
Hamid Hassan Khan ◽  
Syed Fahad Anwer ◽  
Nadeem Hasan ◽  
Sanjeev Sanghi
Keyword(s):  
Finite Length ◽  
Square Duct ◽  
Laminar To Turbulent Transition ◽  
Turbulent Transition
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